1. Field of the Invention
The present invention relates to a rotary piston compressor intended for compressing fluids by means of a rotary piston.
More specifically, in a rotary piston pump [Japanese Pat. No. 821,174 (Publication Number 50-35246)] previously developed by the present applicant, a rotary piston compressor using a rotary piston pump and comprising a rotary piston with an approximately oval section is disclosed with Oldham's coupling mechanism disposed inside the cylinder so as to slide along the inside surface. An intake and a discharge for fluid are disposed on either side of the cylinder along a straight line connecting the central point of the eccentric shaft to take advantage of small and large clearance between the rotary piston and the internal circumferential surface of the cylinder due to eccentric rotation of the driving shaft and an off-set shaft, and is characterized in that one side of the shaft of Oldham's coupling mechanism is the drive shaft. An oval rotary piston is disposed in an intermediate position between the driving shaft and the other off-set shaft (called a correcting shaft hereinafter). This rotary piston is disposed to slide along the inside surface of the fixed cylinder, thereby taking advantage of variation of volume between the inside of the cylinder and outside of the rotary piston due to eccentric rotation of the rotary piston thereby forcing intake, compression and discharge of fluid.
2. Description of the Prior Art
Conventional reciprocating piston type compressors are unable to increase velocity due to inertia of the piston system because the piston has to change direction at the top or bottom dead point, so that it has been difficult to design higher speed and miniaturized versions of the compressor. Further, compression occurs at the stage of shifting the piston to the top dead point and only one full compression occurs for each cycle, thereby decreasing the efficiency.
In such rotary piston devices as the Wankel mechanism, the application of pressure to the receiving axis of pressure of the rotary piston acts repeatedly in the same direction so that abrasion in the sliding portion of the rotary piston is great and rotary balance of the rotary piston itself is liable to deteriorate.